The relation between the energies of ion movement and ATP hydrolysis is unknown in tissues with widely varying electric potentials. Consequently, we measured the concentration of the nine major inorganic ions in the extra- and intracellular phases in heart, liver, and red cells with resting electrical potentials, E(N), of -86, -28, and -6 mV, respectively, under six different physiological conditions. We calculated the Nernst electric potential and the energy of ion movement between the phases… CONTINUE READING